Category: Genetics and Obesity
Scientists Seek to Learn More about Human Obesity, Fitness by Studying Mice
At first glance, humans and rodents may not seem to have a whole lot in common with one another, but scientists have increasingly come to rely on these fuzzy little creatures to expand their understanding of obesity and weight loss. Surprisingly enough, mice share enough of our physiological features to be able to stand in for humans in many lab tests, experiments, and studies.
Indeed, most of the medical breakthroughs that have occurred over the course of the last century have their earliest origins in studies conducted using mice. With the epidemic of obesity that is now threatening the health and well-being of many in the Western world, scientists have begun using animal models to try to find out more about not only the causes of obesity, but also possible treatments and solutions for this problem. This week, we?ll take a look at three recent studies that offer new insight into fitness -- and fatness.
Access to Fast Food, Junk Food Can Alter Eating Behaviors
Over the last few years, there has been a firestorm of controversy surrounding the prevalence of unhealthy foods in modern society. Public health advocates have claimed that easy access to fast food has helped contribute to the obesity epidemic, while the companies that offer these products have countered that they can be part of a healthy diet if eaten in moderation.
Inspired by the documentary Super-Size Me, Dr. Brent Tetri, a gastroenterologist and liver specialist at St. Louis University, designed an experiment to test these claims. Dr. Tetri and his team fed a group of mice the nutritional equivalent of a fast-food diet over a period of 16 weeks. This pattern of consumption not only resulted in dire health consequences for the mice, but it also seemed to have impacted their eating preferences and food-seeking behaviors.
From a biological point of view, the fast-food-eating mice suffered from ailments ranging from fatty accumulations on the liver to early-stage diabetes. Perhaps even more disturbingly, however, the fast-food-eating mice soon began to overeat past the point of fullness at every meal time, while their counterparts who were being fed a normal, healthy diet did not do so. According to Tetri and his team, these results may have grave implications for patients attempting to incorporate even moderate fast-food consumption into a healthy lifestyle.
New Shots May Provide Help With Targeted Weight Loss
Doctors and fitness experts have long told their patients that it?s impossible to lose weight in just your problem areas. In order to achieve your ideal shape, it has long been counseled, you have to lose weight everywhere, usually by following a diet and fitness regimen.
However, one recent study suggests that there may be hope for men and women who are more concerned with unsightly fat in just a few trouble spots. A team of scientists led by Dr. Zofia Zukowska of Georgetown University Medical Center in Washington, D.C. were able to use targeted doses of a substance known as neuropeptide Y to reduce fat in certain areas, and encourage its growth in other areas. The procedure could be used to develop new cosmetic surgery techniques in the future, Zukowska noted.
Stress Can Be Directly Related to Weight Gain, Study Finds
Although it has long been assumed that stress and anxiety can promote a tendency toward obesity, the results of a study recently published in the prestigious journal Nature offered a strong confirmation of this supposition. According to the authors, mice who were subjected to stressful conditions developed a strong craving for foods high in carbohydrates.
In addition, the same chemical compound that caused the cravings also helped convert the excess calories eaten by stressed-out mice into fat deposits centered around the stomach area. In humans, belly fat is the most dangerous pattern of weight gain, linked with a wide variety of ailments and illnesses, including diabetes and heart disease. According to the authors, these findings underscore the importance of stress-relieving activities as part of a healthy lifestyle.
Be sure to check back each week for more of the weight loss, fitness, and diet news that can help you design and maintain your own healthy lifestyle.
How Can You Tell if You Are Fit or Fat? Recent Studies Weigh In On Obesity Assessment
If you?re among the growing population of people who doctors classify as clinically obese, you probably already recognize that you could drastically improve your health, well-being, and lifestyle by shedding a few excess pounds. When you?re carrying a significant amount of extra weight around, it?s not difficult to determine that a lifestyle change is in order.
But for people who are closer to the weight range typically defined as ?normal? for their age, gender, and body type, determining whether a lifestyle change is necessary can be much more challenging. Doctors, health advocacy organizations, and medical researchers often have starkly different points of view on this issue, as evidenced by the vast array of assessment tools that are currently being used to set the ranges that constitute healthy and unhealthy weights for each person.
The challenge of identifying the best tool for assessing weight is one of the most significant -- and controversial -- issues facing medical researchers today. This week, we?ll take a look at a few recent studies that have sought to shed some light on this subject.
Recent Study Questions Validity of BMI Scale
The Body-Mass Index has long been regarded as one of the most reliable techniques for assessing the healthiness of an individual?s weight. It uses weight, height, and, in some cases, frame size to calculate a number that indicates whether an individual is a healthy weight, overweight, or obese.
Although the BMI scale has a number of inherent limitations, it has long been regarded as the default method of obesity assessment. In particular, scientists conducting large-scale research projects have come to rely upon the BMI scale as a method of classifying study participants as normal, overweight, or obese based on a few key pieces of height and weight data.
However, over the last several years, concerns about the efficacy of the BMI scale have begun to accumulate rapidly. A growing number of critics have questioned whether researchers, doctors, and public health advocacy groups alike have become overly reliant on BMI assessment.
These criticisms seem to have been validated, at least in part, by the results of a recent study conducted by a research team at the Harvard Medical School. According to the findings, the BMI scale has several significant shortcomings. Most notably, the BMI scale tends to over-identify athletes as overweight or obese, while giving a free pass to skinny but out-of-shape individuals. The obesity levels of the elderly are also often underestimated on the BMI scale, because they tend to have less muscle mass than their younger counterparts.
The researchers suggested that the ratio of the measurement of the waist to the measurement of the hips may represent a much more accurate method for obesity assessment. This method more accurately reflects the negative health impact of excessive fat around the midsection, which is widely agreed to be a sign that weight loss efforts are necessary. Although the BMI will likely continue to be used in some situations, researchers caution that it should not be regarded as an infallible measure of obesity.
Study Sheds Light on the Role of the Scale in Weight Loss
For dieters, the scale can be both your best friend and your worst enemy. On the positive side, frequent weighing can help us keep close tabs on our progress and make adjustments according to even small fluctuations in weight. On the other hand, excessive reliance on the scale can lead to frustration and disappointment -- and, some researchers fear, the abandonment of weight loss efforts altogether. As a result, some diet gurus have begun to advise those seeking to shed excess pounds to look to other methods of keeping track of their progress, such as paying attention to the way clothes fit and taking body measurements.
However, a recent study conducted by scientists at the University of Minnesota indicates that the scale may be a useful tool in weight loss efforts, after all. Over the course of two years, individuals who weighed themselves more frequently were shown to have lost more weight and gained less weight back than their counterparts who rarely or never weighed themselves. However, the researchers caution that dieters should avoid becoming excessively reliant on the scale, and to measure their weight loss progress in other ways, as well.
Research Indicates 'Skinny' Does Not Always Mean 'Healthy'
We tend to make a lot of snap judgments about people's weight and health based on their outward appearance. Often, it?s assumed that men and women who appear to be thin are fit and healthy, while more rotund individuals are automatically believed to be at greater health risk.
However, according to the results of a recent study funded by Britain's Medical Research Council, these assumptions may not always accurate. Apparently, not all fat is created equally. Studies show that fat that is gathered around the midsection or collected around the internal organs may be disproportionately harmful.
Interestingly, people who appear thin can be at high risk for these kinds of fatty deposits. According to the researchers, everyone should be vigilant for signs of internal or external fat accumulation, regardless of their body size.
No matter which method of measurement you prefer, it's important to keep tabs on your weight so you will be better equipped to stay within an optimal range. And don't forget to check back each week for the breaking research news that will help you create and maintain a healthy lifestyle!
The Great Debate Continues: Recent Findings About Genetic Causes of Obesity
When it comes to weight loss, one of the most heated controversies is a variation of the age-old ?nature or nurture? debate that scientists have long asked about many aspects of human health and behavior. In short, is obesity caused by our genetics, environment and upbringing, or by our family?s and ancestors? health, heritage, and medical history?
The question is so complex that it cannot be easily answered. Although scientists have been exploring this issue for decades, a definitive answer to the ?nature or nurture? question has remained elusive. Because the transmission and manifestation of genetic traits is such a complicated process that depends upon many variables, it may be that a simple ?yes? or ?no? answer to this question will never be possible.
Still, researchers continue to investigate the relationship between obesity and genetics, with significant new findings being announced on an ongoing basis. Here?s an overview of some of the most groundbreaking findings that have been released in recent months.
UK Researchers Uncover a Strong Genetic Link to Obesity
The results of a recent study conducted by UK researchers at the University of Oxford and the Peninsula Medical School in Exeter added fuel to the flames of the ?nature or nurture? controversy. According to the team?s findings, the presence of a certain gene was identified as increasing an individual?s risk of becoming obese by up to 70%.
The gene in question was referred to as the ?FTO? gene. Among a test group of over 40,000 subjects, it was found that individuals whose DNA had one copy of the FTO gene stood a 30% higher risk of developing obesity in adulthood. The individuals who had two copies of the FTO gene (i.e., one from each parent) bore a remarkable 70% greater risk of obesity than did their counterparts without the gene.
Relationship between Mother?s Age at Puberty and Childhood Obesity Probed
A research team based at the University of Cambridge recently released study findings that identified a possible connection between maternal menarche and the obesity risk of children, offering another perspective on the long-running debate over the role genetics play in determining weight.
Specifically, the researchers found that women who started menstruating earlier tended to have children who developed obesity during childhood and adolescence. Women whose first menstrual period began at or before age 11 typically gave birth to children who experienced rapid growth during their first two years of life, but then began to develop obesity and comparatively short stature in relation to their peers.
The researchers pointed out that girls born to women who began menstruation at an early age were also more likely to experience early menstruation themselves, which is another risk factor for obesity in adolescence and adulthood.
Study Identifies Genetic Differences in the Way Nutrients are Processed
A research team comprised of scientists from Tufts University and the US Department of Agriculture Human Nutrition Research Center found that different people process fat, protein, and carbohydrates differently, and that these differences can be partially ascribed to genetic traits.
Specifically, the researchers found that for a small number of people with a genetic variant of the APOA5 gene, fat intake did not impact overall body mass (BMI). In other words, the estimated 13% of the population with this gene can eat what most would consider to be an unhealthy diet and still maintain a generally healthy weight. Although this finding is not directly related to the genetic causes of obesity, it does suggest that a strong link does exist between genetics, our physique, and the ease with which we can (or can?t) maintain a healthy weight.
Nature and Nurture
Although these recent findings suggest that there is a strong link between genetics and obesity, don?t despair. As scientists would be the first to remind you, even if you have the genes that increase your risk for a condition, that doesn?t mean you?re doomed to a lifelong struggle with weight gain. Genetic expression results from a combination of our DNA and our daily choices.
In other words, if you maintain a reasonably healthy diet and exercise regularly, you probably won?t become overweight, even if you are genetically predisposed to it. As with so many things in life, if you stick to a path of moderation, you can decide your own destiny.
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